Primary Posterior Mediastinal Goiter:A rare cause of dyspnea
Primer Posterior Mediastinal Guatr: Nadir Bir Dispne Sebebi
Leyla Hasd1raz,
MD.,
Department of Cardiovascular and Thoracic Surgery, Erdyes University Medical Faculty
lhasdiraz@erciyes.edu.tr
Mehmet Bilgin,
MD.,
Department of Cardiovascular and Thoracic Surgery, Erciyes University t>ledical Faculty
Fahri Oguzkaya,
MD.,
Department of Cardiovascular and Thoracic Surgery, Eretyes University Medical Faculty
This manuscript can be downloaded from the webpage:
http :I /t i pd~ 11J isi. err.iycs. ed u . tr I Pro)cct6/200 7; 7.9( 5) 412 ·414. pdf
Submitted Revised Accepted
: October 11, 2006 : February 26, 2007 : March 28, 2007
Corresponding Author: Leyla Hasd1raz,
Departrnent of Cardiovascular and Thoracic Surgery, Erciyes University Medical Faculty
Kayseri, Turj...ey
Telephone E·mail
412
: +90 . 352 4374937 : lhasdiraz@erciyes.edu.tr
Abstract
Abstract EctopiC 1ntrathorac1c thyroid IS a rare presentation of thyrOid d1sease and compnses about 1% of all mediastmal tumors. Although, 1t 1s occult on chest radiographs, mtrathorac1c thyroid masses are ev1dent as antenor mediastinal masses. We present a pat1ent w1th pnmary ectop1c left post en or med1astmal go1ter, caused by dyspnea due to tracheal compression.
Left postero lateral thoracotomy was performed to remove the mass, resultmg 1n a favorable outcome.
Key Words: Ectopic goiter; Posterior mediastinum; Surgery.
Ozet
Ektop1k mtratoras1k t1r01d nad1rd1r ve tum med1ast1nal k1tlelenn yakla~1k %1 'm1 olu~turur.
Intratorasik t1ro1dlenn ~ogu antenor med1astmal k1tle olarak rontgenogramla tesb1t ed1leb111r.
B1z, trakeaya basi yaparak d1spneye sebep clan sol postenyor med1ast1nal yerle~1mll pnmer cktop1k guatrll olgumuzu sunuyoruz. Sol posterolateral torakotom1 1le k1tle ba!;anll b1r ,ekllde
~1kanlm1,t1r.
Anahtar kehmeler: Ektopik guatr; Postenyor mediasten; Cerrahi.
Erciyes T1p Dergisi (Erciyes Medical Journal) 2007 ;29(5) :412-414
Primary Po:-;terior Medias/ina! Goiter:.l rare cause vf.-~rspnea
Introduction:
Primary mediastinal ectopic goiters are very rare and comprise about 1% of all mediastinal tumors. Enlarged mediastinal thyroid tissue may result from extension of a cervical goiter into the chest and is then called secondary or may develop from ectopic thyroid tissue located in the mediastinum and is then called primary (1 ). Blood supply of primary mediastinal goiter comes from local intrathoracic vessels. Compressing symptoms, diagnostic uncertainty, and the risk of malignancy support surgical
eXCISIOn.
Case report
The patient is a 74-year-old man with a 2-month history of progressive dyspnea. Chest x-ray showed the left superior mediastinal mass was compressing the trachea.
A computed tomography (CT) scan confirmed a posterior mediastinal (retrotracheal visceral mediastinum) mass with no cervical connections. (Fig. 1) The physical examination revealed no abnormalities but stridor.
Hematological and chemistry panels were normal. A left posterolateral thoracotomy was performed. The mass was, behind the arcus aorta, left carotid and subclavian arteries.
Although the mass was pushing the trachea through the right hemithorax, there was no invasion. On the other hand, the esophagus was compressed to the right and posterior aspect of the thorax. In addition, there was a 1 Ocm contact between the columna vertebrates and the mass. Mobilization of the mass encountered no communication with the cervical thyroid, and all blood supply to the mass was intrathoracic. The specimen was solid, and measured 12 x 7 x 5 em. Histological examination was representative of multinodular goiter.
Picture 1. CT scan showing a big posterior mediastinal goiter.
Erciyes Tip Dergisi (Erciyes Medical Journal) 2007;29(5):412-414
Discussion
Ectopic intrathoracic thyroid is a rare presentation of thyroid disease and comprises about 1% of all mediastinal tumors (2). The left posterior mediastinal location of thyroid gland is rare. The anterior mediastinum makes up 75% to 94% of intrathoracic goiters. The posterior mediastinal masses constitute 10% to 15%. The right posterior mediastinum is the most common location, in which the aortic arch development blocks descent to the left (3).
Foregut endoderm is the embryonic origin of thyroid gland, which migrates ventrocaudally with the great vessels into the chest, and abenant tissue can occur with continued migration. The "true" aberrant thyroid is distinguished from a substernal goiter or thyroid tissue by its lack of connection to the prim my gland ( 4 ). However, aberrant, benign ectopic thyroid tissue may occur, and it is most commonly found as a part of the evaluation of endocrine dysfunction and rarely presents as a primary mass (5).
Symptoms at presentation vaty and range from minimal to disabling. These include cough, pain, neck swelling, dysphagia, superior vena cava syndrome, or dysfunction of the recurrent latyngeal nerve (2, 6). Our patient has admitted to our clinic with progressive dyspnea and stridor.
The diagnostic procedures include standard X-ray and CT scan imaging, eventually combined with radionuclide scintigraphy. Once the diagnosis of a intrathoracic goiter is obtained the treatment is surgical because of unknown dignity, risk of compression or other symptoms (7).
Primary posterior mediastinal goiters are best operated by thoracotomy as troublesome mediastinal bleeding may occur which is difficult to control from a cervical collar incision. The approach of choice is a posterolateral thoracotomy in case of a posterior location. Arcus aorta and its branches may cause difficulties to approach superior posterior mediastinum on the left side.
In conclusion, primary posterior mediastinal masses are rarely thyroid gland and the treatment is surgical if the mass causes symptoms due to compression.
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